Mold Growth

An experiment was conducted to illustrate factors regarding mold growth including the time frame, conditions, and outcomes. The five samples were divided at the same time from the same source. Random amounts of water were added to each sample in the beginning of the experiment.

Mycotoxins cannot be seen even under a regular microscope. However, mold that produces them can be seen easily. While not all molds produce mycotoxins, all molds lower the value of stored grain because they grow by eating it. However, the mold we see may be brushed off but have mycotoxins remain in the kernel.

The samples were kept in different rooms at room temperature in the same building.

Picture 1 is corn that had been stored properly for 18 months and was the source for the samples in the subsequent 5 pictures.

(This is not purported to be a scientifically controlled experiment. While repeatable in substance, the outcomes will vary dependent on the levels of MC, spore exposure and other factors. Rather it is simply to illustrate basics — including speediness — regarding mold growth on grain).

Notice several aspects of this experiment:

► each started with equivalent corn from the same source;

► each was placed within the same building with approximately the same temperature;

► each had been exposed to the same spores of mold from the field and through 18 months of storage;

► each may have been exposed to different spores present in the different rooms in which they were placed;

► each had random amounts of water added — notice the comments below the pictures.

1st Sample – Corn stored 18 months

This corn was harvested and stored properly for 18 months. The following samples were taken from this original lot and subjected to different conditions for up to 18 days. This shows that grain can be stored for long periods of time with little loss (no deterioration but likely some loss of viability of vitamins, enzymes and similar biotic constituents) and that spoilage is conditions based, not time based. Once spoilage starts it progresses very rapidly.

Sample 2 – 6 days later

There was sufficient moisture added to this sample to stimulate sprouting in less than a week. Notice that a type of fungus also became active.

Sample 3 – 16 days later

This illustrates further growth in just over 2 weeks.

Sample 4 – 18 days later

This sample had enough water to stimulate fungus growth but not enough to start sprouting. Notice that a different fungus responded to the lower level of moisture than on other samples.

Sample 5 – 18 days later

Sprouting and mold growth are both rampant in this sample.

Sample 6 – 18 days later

In less than three (3) weeks corn that had been preserved nearly perfectly for eighteen (18) months degraded substantially. This is preventable with proper storage infrastructure and aeration practices.